Firewood
Have you heard about the mad chainsaw man?--------ohhh!
Seriously, though, I used firewood till the winter before last, although mine came in the form of "split jarrah"blocks (actually more like "lumps").
The "blocks" were often a lot larger than my fireplace, so I had a manual "block splitter" (hybrid between an axe & sledgehammer) to reduce their size.
Jarrah has delusions of grandeur, is not content with just being wood, & aspires towards iron, so it is great exercise splitting it.
As I am seriously past that stuff, we now have a "reverse cycle" airconditioner which also cools us in the Summer!